Superconductive magnet apparatus and magnetic resonance imaging apparatus

Abstract

A cryostat is formed into a donut form, where a cylindrical or a square concave is formed in the center of the cryostat of the superconductive magnet apparatus for an open type MRI apparatus, and the cryo-compressor is disposed in the concave.

1. A superconductive magnet apparatus, which comprises:
 a cryostat comprising a pair of ring shaped superconductive coils; a pair of coil containers each including one of the superconductive coils and for accommodating a cooling medium; a pair of thermal shields each covering one of the coil containers; and a pair of vacuum vessels each covering one of the thermal shields, and a cryo-compressor for cooling the cooling medium, wherein the coil containers are disposed so as to face each other, and a magnetic field space is formed in a bore or space between the coil containers, the cryo-compressor being disposed inside of the superconductive coils and within a concavity formed in one of the vacuum vessels of the cryostat. 
 
     
     
       2. The superconductive magnet apparatus according to  claim 1 , wherein the cryo-compressor is disposed in parallel with the direction of the magnetic field in the magnetic space. 
     
     
       3. A magnetic resonance imaging apparatus comprising the superconductive magnetic apparatus according to  claim 2 , a bed or table for carrying a body to be inspected, and a controller for analyzing nuclear magnetic resonance signals from the body, the bed or table being movable between the opposite vacuum vessels of the superconductive magnetic apparatus. 
     
     
       4. The superconductive magnetic apparatus according to  claim 1 , wherein the cryo-compressor is disposed in a diagonal direction with respect to the direction of the magnetic field in the magnetic space. 
     
     
       5. A magnetic resonance imaging apparatus comprising the superconductive magnetic apparatus according to  claim 4 , a bed or table for carrying a body to be inspected, and a controller for analyzing nuclear magnetic resonance signals from the body, the bed or table being movable between the opposite vacuum vessels of the superconductive magnetic apparatus. 
     
     
       6. The superconductive magnetic apparatus according to  claim 1 , wherein the cryo-compressor is disposed in such a position that the strength of an experience magnetic field is low. 
     
     
       7. A magnetic resonance imaging apparatus comprising the superconductive magnetic apparatus according to  claim 1 , a bed or table for carrying a body to be inspected, and a controller for analyzing nuclear magnetic resonance signals from the body, the bed or table being movable between the opposite vacuum vessels of the superconductive magnetic apparatus. 
     
     
       8. A superconductive magnet apparatus, which comprises:
 a cryostat comprising a pair of superconductive coils; a pair of coil containers each accommodating one of the coils and a cooling medium; a pair of thermal shields each covering one of the coil containers with a space; and a vacuum vessel for covering the coil containers and the thermal shield, the vacuum vessel being kept at a vacuum; and a cryo-compressor for cooling the cooling medium, wherein the coil containers are so disposed as to face each other to form a magnetic space between the coil containers, characterized in that there is disposed a shield coil for shielding the magnetic field of the superconductive coils, and the cryo-compressor is disposed within a concavity formed in a wall of one of the coil containers near the shield coil and outside the cryostat. 
 
     
     
       9. The superconductive magnet apparatus according to  claim 8 , wherein the cryo-compressor is disposed on a path connecting the center of the magnetic space and the shield coils. 
     
     
       10. The superconductive magnet apparatus according to  claim 8 , wherein the cryo-compressor is disposed at a position where an experience magnetic field strength is weak. 
     
     
       11. A superconductive magnet apparatus, which comprises:
 a cryostat comprising a pair of superconductive coils; a pair of coil containers for accommodating each of the superconductive coils and a cooling medium; a pair of thermal shields for covering the coil containers with a space; and a cryo-compressor for cooling the cooling medium, wherein the coil containers are so disposed as to face each other thereby to form a magnetic space between the coil containers, the cryo-compressor being disposed within a concavity outside the cryostat where an experience magnetic strength is weak, the concavity being formed in one of the coil containers. 
 
     
     
       12. The superconductive magnet apparatus according to  claim 11 , which further comprises a pair of shield coils for shielding the magnetic field of the superconductive coils, wherein the cryo-compressor is disposed at a position where the experience magnetic strength is weak. 
     
     
       13. A superconductive magnetic apparatus, which comprises:
 a cryostat comprising a pair of superconductive coils; a pair of coil containers each accommodating one of the superconductive coils and a cooling medium; a pair of thermal shields each covering one of the coil containers; and a vacuum vessel covering each of the thermal shields, and a cryo-compressor for cooling the cooling medium; 
 wherein the coil containers are disposed so as to face each other, and a magnetic field space is formed in a bore between the coil containers, the cryo-compressor being disposed within a concavity being formed in a wall of the vacuum vessel of the cryostat outside the cryostat. 
 
     
     
       14. The superconductive magnetic apparatus according to  claim 13 , wherein the cryo-compressor is located inside of one of the superconductive coils. 
     
     
       15. The superconductive magnetic apparatus according to  claim 13 , wherein the cryo-compressor is disposed at a position where an experience magnetic strength is weak. 
     
     
       16. The superconductive magnetic apparatus according to  claim 13 , wherein the coil containers are characterized in that there is disposed a shield coil for shielding the magnetic field of the superconductive coils, and the cryo-compressor is disposed within the concavity formed in the wall of one of the coil containers near the shield coil.